Method for producing surfactant alcohols and surfactant alcohol ethers, the resulting products and their use

ABSTRACT

The invention describes a process for the preparation of novel surfactant alcohols and surfactant alcohol ethers by derivatization of olefins having from about 10 to 20 carbon atoms or of mixtures of such olefins to give alkanols, and optional subsequent alkoxylation, which comprises 
     subjecting a C 4 -olefin mixture to metathesis, dimerizing the resulting olefins, and then derivatizing them to give surfactant alcohols, and optionally alkoxylating said alcohols. 
     The olefin mixture obtained in the dimerization has a high proportion of branched components and less than 10% by weight of compounds which contain a vinylidene group. 
     The invention further describes the use of the surfactant alcohols and surfactant alcohol ethers to give surfactants by glycosylation or polyglycosylation, sulfation or phosphation.

This application is a 371 of PCT/EP99/10237, filed Dec. 21, 1999.

The present invention relates to a process for the preparation ofsurfactant alcohols and surfactant alcohol ethers which, inter alia, arehighly suitable as surfactants or for the preparation of surfactants. Inthe process, starting from C₄-olefin streams, olefins or olefin mixturesare prepared by a metathesis reaction which are dimerized to give anolefin mixture having from 10 to 16 carbon atoms, which comprises lessthan 10% by weight of compounds which have a vinylidene group, then theolefins are derivatized to give surfactant alcohols and said alcoholsare optionally alkoxylated.

The invention further relates to the use of the surfactant alcohols andsurfactant alcohol ethers for the preparation of surfactant byglycosylation or polyglycosylation, sulfation or phosphation.

Fatty alcohols having chain lengths from C₈ to C₁₈ are used for thepreparation of nonionic surfactants. They are reacted with alkyleneoxides to give the corresponding fatty alcohol ethoxylates. (Chapter 23in: Kosswig/Stache, “Die Tenside” [Surfactants], Carl Hanser Verlag,Munich Vienna (1993)). The chain length of the fatty alcohol influencesthe various surfactant properties, such as, for example, wettingability, foam formation, ability to dissolve grease, cleaning power.

Fatty alcohols having chain lengths from C₈ to C₁₈ can also be used forpreparing anionic surfactants, such as alkyl phosphates and alkyl etherphosphates. Instead of phosphates, it is also possible to prepare thecorresponding sulfates. (Chapter 2.2. in: Kosswig/Stache “Die Tenside”[Surfactants], Carl Hanser Verlag, Munich Vienna (1993)).

DE-A-196 04 466 is concerned with aqueous compositions containing analkylglycoside and a polyethyleneglycol derivative of formula I given inthis document.

The alkyl group R² (Page 2, line 55) has 8 to 18, preferably 10 to 16carbon atoms; no direct information is given in this document about thedegree of branching. One can, however, conclude that the alkyl groupmust be predominantly linear, because it is said that it has beenobtained by hydrogenation of native fatty acids.

Such fatty alcohols are obtainable from native sources, e.g. from fatsand oils, or else in a synthetic manner by constructing building blockshaving a lower number of carbon atoms. One variant here is thedimerization of an olefin to give a product having twice the number ofcarbon atoms and its functionalization to give an alcohol.

For the dimerization of olefins, a number of processes are known. Forexample, the reaction can be carried out over a heterogeneous cobaltoxide/carbon catalyst (DE-A-1 468 334), in the presence of acids such assulfuric or phosphoric acid (FR 964 922), with an alkyl aluminumcatalyst (WO 97/16398), or with a dissolved nickel complex catlyst U.S.Pat. No. 4,069,273). According to the details in U.S. Pat. No.4,069,273, the use of these nickel complex catalysts (the complexingagent used is 1,5-cyclooctadiene or1,1,1,5,5,5-hexafluoropentane-2,4-dione) gives highly linear olefinswith a high proportion of dimerization products.

DE-A-43 39 713 (D1) is concerned with a process of oligomerization ofolefins using catalysts, which have been tailored so that there areobtained extraordinary high proportions of linear reaction products,which are particularly desired with this process.

Working Examples 3 to 5 of tis document shows oligomerization ofbutan/butene-mixtures, whereby reactin products are obtained containing62 to 78% by weight of Octen. This known procedure comprises nometathesis and the reaction products disclosed therein do not consist ofcomponents having 10 to 16 carbon atoms.

U.S. Pat. No. 3,448,163 (D3) is concerned with a process fordiproportionation of olefins and catalysts, which are particularlyuseful for this process. In the Working Example there is shown thatbutene-1 is transformed into a mixture of olefins having 2 to 7 carbonatoms, particularly ethylene and hexene-3. this known process comprisesno dimerisation step and the reaction product disclosed therein does notconsist of components having 10 to 16 carbon atoms.

Functionalization of the olefins to give alcohols with construction ofthe carbon skeleton about a carbon atom expediently takes place via thehydroformulation reaction, which gives a mixture of aldehydes andalcohols, which can then be hydrogenated to give alcohols. Approximately7 million metric tons of products per annum are produced worldwide usingthe hydroformylation of olefins. An overview of catalysts and reactionconditions for the hydroformylation process are given, for example, byBeller et al. In Journal of Molecular Catalysis, A104 (1995), 17-85 andalso in Ullmann's Encyclopedia of Industrial Chemistry, vol. A5 (1986),page 217 et seq., page 333, and the relevant literature references.

GTB-A-1 471 481 (D2) is concerned with a process for hydroformylationolefins using a catalyst containing cobalt. The olefins introduced inthis process are linear and, hence, oxoalcohols an oxoaldeydes areobtained having a low degree of branching.

p From WO 98/23566 it is known that sulfates, alkoxylates,alkoxysulfates and carboxylates of a mixture of branched alkonols (oxoalcohols) exhibit good surface activity in cold water and have goodbiodegradability. The alkonols in the mixture used have a chain lengthof greater than 8 carbon atoms, having on average from 0.7 to 3branches. The alkanol mixture can, for example, be prepared byhydroformylation, from mixtures of branched olefins which for their partcan be obtained either by skeletal isomerization or by dimerization ofinternal, linear olefins.

A given advantage of the process is that a C₃- or C₄-olefin stream isnot used for the preparation of the dimerization feed. It follows fromthis that, according to the current prior art, the olefins subjected todimerization therein must have been prepared from ethylene (e.g. SHOPprocess). Since ethylene is a relatively expensive starting material forsurfactant manufacture, ethylene-based processes have a costdisadvantage compared with processes which start from C₃- and/orC₄-olefin streams.

Another disadvantage of this known process is the use of mixtures ofinternal olefins, which are only obtainable by isomerization ofalpha-olefins, which is required for the preparation of branchedsurfactant oxo alcohols. Such processes always lead to isomer mixtureswhich, because of the varying physical and chemical data of thecomponents, are more difficult to handle in terms of process engineeringthan pure substances. Furthermore, the additional process step ofisomerization is required, by virtue of which the process has a furtherdisadvantage. The dimerization of a pure internal olefin, such as2-pentene or 3-hexene, and the further dimerization of the dimerizationproducts have not been described previously.

The structure of the components of the oxo alkanol mixture depends onthe type of olefin mixture which has been subjected to hydroformylation.Olefin mixtures which have been obtained by skeletal isomerization fromalpha-olefin mixtures lead to alkanols which are branched predominantlyat the ends of the main chain, i.e. in positions 2 and 3, calculatedfrom the end of the chain in each case (page 56, last paragraph). Olefinmixtures which have been obtained by dimerization of olefins of shorterchain lengths give, by the process disclosed in this publication, oxoalcohols whose branches are more in the middle of the main chain and, asTable IV on page 68 shows, very predominantly on C4 and further removedcarbon atoms, relative to the hydroxyl carbon atoms. By contrast, lessthan 25% of the branches are at the C2 and C3 positions, relative to thehydroxyl carbon atom (pages 28/29 of this document).

The surface-active end products are obtained from the alkanol mixtureseither by oxidation of the —CH₂OH group to give the carboxyl group, orby sulfation of the alkanols or their alkoxylates.

Similar processes for the preparation of surfactants are described inthe PCT Patent Application WO 97/38957 and in EP-A-787 704. Also in theprocesses described therein, an alpha-olefin is dimerized to give amixture of predominantly vinylidene-branched olefin dimers (WO97/38957):

The vinylidene compounds are then double-bond-isomerized, such that thedouble bond migrates from the end of the chain further into the center,and are then subjected to hydroformylation to give an oxo alcoholmixture. The latter is then further reacted, e.g. by sulfation to givesurfactants. A serious disadvantage of this process is that it startsfrom alpha-olefins. Alpha-olefins are obtained, for example, bytransition-metal-catalyzed oligomerization of ethylene, Ziegler build-upreaction, wax cracking or Fischer-Tropsch processes and are thereforerelatively expensive starting materials for the manufacture ofsurfactants. A further considerable disadvantage of this knownsurfactant preparation process is that a skeletal isomerization must beinserted in the process between the dimerization of the alpha-olefinsand the hydroformylation of the dimerization product if predominantlybranched products are desired. Because it uses a starting material whichis relatively expensive for surfactant manufacture and because of theneed to insert an additional process step, the isomerization, this knownprocess is at a considerable disadvantage in terms of cost.

Surprisingly, we have now found that branched olefins and alcohols (oxoalcohols), which can be further processed to give very highly effectivesurfactants—referred to below as “surfactant alcohols” —, can beprepared using neither alpha-olefins nor olefins which have beenprepared mainly from ethylene, but starting from cost-effectiveC₄-olefin streams, and that, furthermore, the isomerization stage can beavoided if the process is carried out according to the invention asdescribed below. C₄-olefin streams are mixtures which consistessentially, preferably in an amount from greater than 80 to 85% byvolume, in particular in an amount of greater than 98% by volume, of1-butene and 2-butene, and to a lesser extent comprise, normally in anamount no more than 15 to 20% by volume, n-butane and isobutane inaddition to traces of C₅ hydrocarbons. These hydrocarbon mixtures,referred to in the jargon also as “raffinate II”, form as by-product inthe cracking of high molecular weight hydrocarbons, e.g. of crude oil.While the low molecular weight olefins produced in this process, etheneand propene, are desired raw materials for the preparation ofpolyethylene and polypropylene, and the hydrocarbon fractions above C₆are used as fuels in combustion engines and for heating purposes, it hashitherto not been possible to further process raffinate II, inparticular its C₄-olefins, to a sufficient extent to give end productsof value. The term C₄-olefin streams used below should therefore alsoencompass the gas mixture referred to as raffinate II.

The process according to the invention now opens up a method, veryfavorable according to the process, of processing the C₄-olefin streamswhich are produced to give surfactant alcohols of value, from whichthen, by various methods known per se, nonionic or anionic surfactantscan be prepared.

This invention provides a process for the preparation of surfactantalcohols and surfactant alcohol ethers by derivatization of olefinshaving from about 10 to 20 carbon atoms or of mixtures of such olefinsand optionally subsequent alkoxylation, which comprises

a) subjecting a C₄-olefin mixture to metathesis,

b) separating off olefins having from 5 to 8 carbon atoms from themetathesis mixture,

c) subjecting the separated-off olefins individually or as a mixture todimerization to give olefin mixtures having from 10 to 16 carbon atoms,

d) subjecting the resulting olefin mixture, optionally afterfractionation, to derivatization to give a mixture of surfactantalcohols, and

e) optionally alkoxylating the surfactant alcohols.

The main features of the metathesis used in process step a) have, forexample, been described in Ullmann's Encyclopedia of IndustrialChemistry, 5^(th) edition, volume A18, p. 235/236. Other information oncarrying out the process is given for example, in K. J. Ivin, “OlefinMetathesis, Academic Press, London, (1983); Houben-Weyl, E18, 1163-1223;R. L. Banks, Discovery and Development of Olefin Disproportionation,CHEMTECH (1986), February, 112-117.

Applying the metathesis to the main constituents present in theC₄-olefin streams, 1-butene and 2-butene, in the presence of suitablecatalysts gives olefins having from 5 to 10 carbon atoms, preferablyhaving from 5 to 8 carbon atoms, but in particular 2-pentene and3-hexene.

Suitable catalysts are, preferably, molybdenum, tungsten or rheniumcompounds. It is particularly expedient to carry out the reaction withheterogeneous catalysis, the catalytically active metals being used inparticular in conjunction with supports made from Al₂O₃ or SiO₂.Examples of such catalysts are MoO₃ or WO₃ on SiO₂, or Re₂O₇ on Al₂O₃.

It is particularly favorable to carry out the metathesis in the presenceof a rhenium catalyst since in this case particularly mild reactionconditions are possible. Thus, the metathesis in this case can becarried out at a temperature of from 0 to 50° C. and at low pressuresfrom about 0.1 to 0.2 MPa.

Dimerization of the olefins or olefin mixtures resulting in themetathesis step gives dimerization products which, with regard tofurther processing to surfactant alcohols, have a particularly favorablecomponent and a particularly advantageous composition if a dimerizationcatalyst is used which contains at least one element from subgroup VIIIof the Periodic Table of the Elements, and the catalyst composition andthe reaction conditions are chosen such that a dimer mixture is obtainedwhich comprises less than 10% by weight of compounds which have astructural element of the formula I (vinylidene group)

in which A¹ and A² are aliphatic hydrocarbon radicals. Preference isgiven to using the internal, linear pentenes and hexenes present in themetathesis product for the dimerization. Particular preference is givento using 3-hexene.

The dimerization can be carried out with homogeneous or heterogeneouscatalysis. Preference is given to the heterogeneous procedure since withthis, on the one hand, catalyst removal is simplified, making theprocess more economical, and on the other hand no waste waters injuriousto the environment are produced, as usually form during the removal ofdissolved catalysts, for example by hydrolysis. Another advantage of theheterogeneous process is that the dimerization product does not containhalogens, in particular chlorine or fluorine. Homogeneously solublecatalysts generally contain halide-containing ligands or are used incombination with halogen-containing cocatalysts. From such catalystsystems, halogen can be incorporated into the dimerization products,which considerably adversely affects product quality and furtherprocessing, in particular hydroformylation to give surfactant alcohols.

For the heterogeneous catalysis, use is advantageously made ofcombinations of oxides of metals of subgroup VIII with aluminum oxide onsupport materials made from silicon and titanium oxides, as are known,for example, from DE-A-43 39 713. The heterogeneous catalyst can be usedin a fixed bed—then preferably in coarsely particulate form as 1 to 1.5mm chips—or in suspended form (particle size 0.05 to 0.5 mm). In thecase of a heterogeneous procedure, the dimerization is advantageouslycarried out at temperatures of from 80 to 200° C., preferably from 100to 180° C., at the pressure prevailing at the reaction temperature,optionally also under a protective gas at a pressure above atmospheric,in a closed system. To achieve optimal conversions, the reaction mixtureis circulated several times, a certain proportion of the circulatingproduct being continuously bled out of the system and replaced bystarting material.

In the dimerization according to the invention, mixtures ofmonounsaturated hydrocarbons are obtained whose components predominantlyhave a chain length twice that of the starting olefins.

Within the scope of the details given above, the dimerization catalystand the reaction conditions are advantageously chosen such that at least80% of the components of the dimerization mixture have, in the rangefrom ¼ to ¾, preferably from ⅓ to ⅔, of the chain length of their mainchain, one branch, or two branches to adjacent carbon atoms.

A very characteristic feature of the olefin mixtures prepared accordingto the invention is their high proportion—usually greater than 75%, inparticular greater than 80%—of components containing branches and thelow proportion—usually below 25%, in particular below 20%—of unbranchedolefins. A further characteristic is that at the branching sites of themain chain, predominantly groups having (y−4) and (y−5) carbon atoms arebonded, where y is the number of carbon atoms in the monomer used forthe dimerization. The value (y−5)=0 means that no side chains arepresent.

In the case of C₁₂-olefin mixtures prepared according to the invention,the main chain preferably carries methyl or ethyl groups at thebranching points.

The position of the methyl and ethyl groups on the main chain islikewise characteristic: in the case of monosubstitution, the methyl orethyl groups are in the position P=(n/2)-m of the main chain, where n isthe length of the main chain and m is the number of carbon atoms in theside groups, and in the case of disubstitution products, one substituentis in the position P and the other is on the adjacent carbon atom P+1.The proportions of monosubstitution products (a single branch) in theolefin mixture prepared according to the invention arecharacteristically in total in the range from 40 to 75% by weight, andthe proportions of double-branched components is in the range from 5 to25% by weight.

We have also found that the dimerization mixtures can be furtherderivatized particularly well when the position of the double bondsatisfies certain requirements. In these advantageous olefin mixtures,the position of the double bonds relative to the branches is such thatthe ratio of the “aliphatic” hydrogen atoms to “olefinic” hydrogen atomsis in the range

H_(aliph):H_(olefin)=(2*n−0.5):0.5 to (2*n−1.9):1.9,

where n is the number of carbon atoms in the olefin obtained in thedimerization. (“Aliphatic” hydrogen atoms are defined as those which arebonded to carbon atoms which are not involved in a C═C double bond (pibond), and “olefinic” hydrocarbons are those bonded to a carbon atomwhich participates in a pi bond.) Particular preference is given todimerization mixtures in which the ratio

H_(aliph):H_(olefin)=(2*n−1.0):1 to (2*n−1.9):1.6.

The novel olefin mixtures obtainable by the process according to theinvention and having the structural features given above are likewiseprovided by the present invention. They are useful intermediates inparticular for the preparation, described below, of branched primaryalcohols and surfactants, but can also be used as starting materials inother industrial processes which start from olefins, particularly whenthe end products are to have improved biodegradability.

If the olefin mixtures according to the invention are to be used for thepreparation of surfactants, then they are firstly derivatized byprocesses known per se to give surfactant alcohols.

There are various methods to achieve this, which comprise either thedirect or indirect addition of water (hydration) to the double bond, oran addition of CO and hydrogen (hydroformylation) to the C═C doublebond.

Hydration of the olefins resulting from process step c) is expedientlycarried out by direct water addition with proton catalysis. An indirectroute, for example via the addition of high-percentage sulfuric acid togive an alkanol sulfonate and subsequent hydrolysis to give the alkanol,is, of course, also possible. The more advantageous direct wateraddition is carried out in the presence of acidic, in particularheterogeneous, catalysts and generally at a very high olefin partialpressure and at very low temperatures. Suitable catalysts have proven tobe, in particular, phosphoric acid on supports such as, for example,SiO₂ or Celite, or else acidic ion exchangers. The choice of conditionsdepends on the reactivity of the olefins to be reacted and can routinelybe ascertained by preliminary experiments (lit.: e.g. A. J. Kresge etal. J. Am. Chem. Soc. 93, 4907 (1971); Houben-Weyl vol. 5/4 (1960),pages 102-132 and 535-539). Hydration generally leads to mixtures ofprimary and secondary alkanols, in which the secondary alkanolspredominate.

For the preparation of surfactants, it is more favorable to start fromprimary alkanols. It is therefore preferable to hydroformylate thederivatization of the olefin mixtures obtained from step c) by reactionwith carbon monoxide and hydrogen in the presence of a suitable,preferably cobalt- or rhodium-containing, catalysts to give branchedprimary alcohols.

The present invention thus preferably further provides a process for thepreparation of mixtures of primary alkanols which are suitable interalia for further processing to give surfactants, by hydroformylation ofolefins, which comprises using the olefin mixtures according to theinvention and described above as starting material. A good overview ofthe process of hydroformylation with numerous other literaturereferences can be found, for example, in the extensive article by Belleret al. in Journal of Molecular Catalysis, A104 (1995) 17-85 or inUllmann's Encyclopedia of Industrial Chemistry, vol. A5 (1986), page 217et seq., page 333, and the relevant literature references.

The comprehensive information given therein allows the person skilled inthe art to hydroformylate even the branched olefins according to theinvention. In this reaction, CO and hydrogen are added to olefinicdouble bonds, giving mixtures of aldehydes and alkanols according to thefollowing reaction equation:

A³=hydrocarbon radical)

The molar ratio of n- and iso-compounds in the reaction mixture isusually in the range from 1:1 to 20:1 depending on the hydroformylationprocessing conditions chosen and the catalyst used. The hydroformylationis normally carried out in the temperature range from 90 to 200° and ata CO/H₂ pressure of from 2.5 to 35 MPa (25 to 350 bar). The mixing ratioof carbon monoxide to hydrogen depends on whether the intention is toproduce alkanals or alkanols in preference. The CO:H₂ ratio isadvantageously from 10:1 to 1:10, preferably from 3:1 to 1:3, where, forthe preparation of alkanals, the range of low hydrogen partial pressuresis chosen, and for the preparation of alkanols the range of highhydrogen partial pressures is chosen, e.g. CO:H₂=1:2.

Suitable catalysts are mainly metal compounds of the formula HM(CO)₄ orM₂(CO)₈, where M is a metal atom, preferably a cobalt, rhodium orruthenium atom.

Generally, under hydroformylation conditions, the catalysts or catalystprecursors used in each case form catalytically active species of theformula H_(x)M_(y)(CO)_(z)L_(q), in which M is a metal of subgroup VIII,L is a ligand, which can be a phosphine, phosphite, amine, pyridine orany other donor compound, including in polymeric form, and q, x, y and zare integers depending on the valency and type of metal, and thecovalence of the ligand L, where q can also be 0.

The metal M is preferably cobalt, ruthenium, rhodium, palladium,platinum, osmium or iridium and in particular cobalt, rhodium orruthenium.

Suitable rhodium compounds or complexes are, for example rhodium(II) andrhodium(III) salts, such as rhodium(III) chloride, rhodium(III) nitrate,rhodium(III) sulfate, potassium rhodium sulfate, rhodium(II) orrhodium(III) carboxylate, rhodium(II) and rhodium(III) acetate, rhodium(III) oxide, salts of rhodium(III) acid, such as, for example,trisammonium hexachlororhodate(III). Also suitable are rhodium complexessuch as rhodium biscarbonylacetylacetonate,acetylacetonatobisethylenerhodium(I). Preference is given to usingrhodium biscarbonylacetylacetonate or rhodium acetate.

Suitable cobalt compounds are, for example, cobalt(II) chloride,cobalt(II) sulfate, cobalt(II) carbonate, cobalt(II) nitrate, theiramine or hydrate complexes, cobalt carboxylates, such as cobalt acetate,cobalt ethylhexanoate, cobalt naphthanoate, and the cobaltcaprolactamate complex. Here too it is also possible to use the carbonylcomplexes of cobalt, such as dicobalt octocarbonyl, tetracobaltdodecacarbonyl and hexacobalt hexadecacarbonyl. Said compounds ofcobalt, rhodium and ruthenium are known in principle and are describedsufficiently in the literature, or they can be prepared by the personskilled in the art in a manner analogous to that for compounds alreadyknown.

The hydroformylation can be carried out with the addition of inertsolvents or diluents or without such an addition. Suitable inertadditives are, for example, acetone, methyl ethyl ketone, cyclohexanone,toluene, xylene, chlorobenzene, methylene chloride, hexane, petroleumether, acetonitrile, and the high-boiling fractions from thehydroformylation of the dimerization products.

If the resulting hydroformylation product has too high an aldehydecontent, this can be removed in a simple manner by hydrogenation, forexample using hydrogen in the presence of Raney nickel or using othercatalysts known for hydrogenation reactions, in particular catalystscontaining copper, zinc, cobalt, nickel, molybdenum, zirconium ortitanium. In the process, the aldehyde fractions are largelyhydrogenated to give alkanols. A virtually residue-free removal ofaldehyde contents from the reaction mixture can, if desired, be achievedby posthydrogenation, for example under particularly mild and economicalconditions using an alkali metal borohydride.

The mixtures of branched primary alkanols, preparable byhydroformylation of the olefin mixtures according to the invention, arelikewise provided by the present invention.

Nonionic or anionic surfactants can be prepared from the alkanolsaccording to the invention in a different manner.

Nonionic surfactants are obtained by reaction of the alkanols withalkylene oxides (alkoxylation) of the formula II

in which R¹ is hydrogen or a straight-chain or branched aliphaticradical of the formula C_(n)H_(2n+1), and n is a number from 1 to 16,preferably from 1 to 8. In particular, R¹ is hydrogen, methyl or ethyl.

The alkanols according to the invention can be reacted with a singlealkylene oxide species or with two or more different species. Thereaction of the alkanols with the alkylene oxides forms compounds whichin turn carry an OH group and can therefore react afresh with onemolecule of alkylene oxide. Therefore, depending on the molar ratio ofalkanol to alkylene oxide, reaction products are obtained which havepolyether chains of varying length. The polyether chains can containfrom 1 to about 200 alkylene oxide structural groups. Preference isgiven to compounds whose polyether chains contain from 1 to 10 alkyleneoxide structural groups.

The chains can consist of identical chain members, or they can havedifferent alkylene oxide structural groups which differ from one anotherby virtue of their radical R¹. These various structural groups can bepresent within the chain in random distribution or in the form ofblocks.

The reaction scheme below serves to illustrate the alkoxylation of thealkanols according to the invention using, as example, a reaction withtwo different alkylene oxides which are used in varying molar amounts xand y.

R¹ and R^(1a) are different radicals within the scope of the definitionsgiven for R¹, and R²—OH is a branched alkanol according to theinvention. The alkoxylation is preferably catalyzed by strong bases,which are advantageously added in the form of an alkali metal hydroxideor alkaline earth metal hydroxide, usually in an amount of from 0.1 to1% by weight, based on the amount of the alkanol R²—OH. (cf. G. Gee etal., J. Chem. Soc. (1961), p. 1345; B. Wojtech, Makromol. Chem. 66,(1966), p. 180).

Acidic catalysis of the addition reaction is also possible. As well asBronsted acids, Lewis acids, such as, for example, AlCl₃ or BF₃, arealso suitable (cf. P. H. Plesch, The Chemistry of CationicPolymerization, Pergamon Press, New York (1963).

The addition reaction is carried out at temperatures of from about 120to about 220° C., preferably from 140 to 160° C., in a sealed vessel.The alkylene oxide or the mixture of different alkylene oxides isintroduced into the mixture of alkanol mixture according to theinvention and alkali under the vapor pressure of the alkylene oxidemixture prevailing at the chosen reaction temperature. If desired, thealkylene oxide can be diluted by up to about 30 to 60% using an inertgas. This leads to additional security against explosion-likepolyaddition of the alkaline oxide.

If an alkylene oxide mixture is used, then polyether chains are formedin which the various alkylene oxide building blocks are distributed invirtually random manner. Variations in the distribution of the buildingblocks along the polyether chain arise due to varying reaction rates ofthe components and can also be achieved arbitrarily by continuousintroduction of an alkylene oxide mixture of a program-controlledcomposition. If the various alkylene oxides are reacted successively,then polyether chains having block-like distribution of the alkyleneoxide building blocks are obtained.

The length of the polyether chains varies within the reaction product ina random manner about a mean, which essentially [lacuna] thestoichiometric value arising from the amount added.

The alkoxylates preparable from alkanol mixtures and olefin mixturesaccording to the invention are likewise provided by the presentinvention. They exhibit very good surface activity and can therefore byused as neutral surfactants in many areas of application.

Starting from the alkanol mixtures according to the invention, it isalso possible to prepare surface-active glycosides and polyglycosides(oligoglycosides). These substances too have very good surfactantproperties. They are obtained by single or multiple reaction(glycosylation, polyglycosylation) with mono-, di- or polysaccharideswith the exclusion of water and with acid catalysis. Suitable acids are,for example, HCl or H₂SO₄. As a rule, the process producesoligoglycosides having random chain length distribution, the averagedegree of oligomerization being from 1 to 3 saccharide radicals.

In another standard synthesis, the saccharide is firstly acetalated withacid catalysis with a low molecular weight alkanol, e.g. butanol, togive butanol glycoside. This reaction can also be carried out withaqueous solutions of the saccharide. The lower alkanol glycoside, forexample butanol glycoside, is then reacted with the alkanol mixturesaccording to the invention to give the desired glycosides according tothe invention. After the acidic catalyst has been neutralized, excesslong-chain and short-chain alkanols can be removed from the equilibriummixture, e.g. by distillation under reduced pressure.

Another standard method proceeds via the O-acetyl compounds ofsaccharides. The latter are converted, using hydrogen halide preferablydissolved in glacial acetic acid, into the correspondingO-acetylhalosaccharides, which react in the presence of acid-bindingagents with the alkanols to give the acetylated glycosides.

Preferred for the glycosylation of the alkanol mixtures according to theinvention are monosaccharides, either hexoses, such as glucose,fructose, galactose, mannose, or pentoses, such as arabinose, xylose orribose. Particular preference for glycosylation of the alkanol mixturesaccording to the invention is glucose. It is, of course, also possibleto use mixtures of said saccharides for the glycosylation. Glycosideshaving randomly distributed sugar radicals are obtained, depending onthe reaction conditions. The glycosylation can also take place severaltimes resulting in polyglycoside chains being added to the hydroxylgroups of the alkanols. In a polyglycosylation using differentsaccharides, the saccharide building blocks can be randomly distributedwithin the chain or form blocks of the same structural groups.

Depending on the reaction temperature chosen, furanose or pyranosestructures can be obtained. To improve the solubility ratios, thereaction can also be carried out in suitable solvents or diluents.

Standard processes and suitable reaction conditions have been describedin various publications, for example in “Ullmann's Encyclopedia ofIndustrial Chemistry”, 5th edition vol. A25 (1994), pages 792-793 and inthe literature references given therein, by K. Igarashi, Adv. Carbohydr.Chem. Biochem. 34, (1977), pp. 243-283, by Wulff and Röhle, Angew. Chem.86, (1974), pp. 173-187, or in Krauch and Kunz, Reaktionen derorganischen Chemie [Reactions in Organic Chemistry], pp. 405-408,Hüithig, Heidelberg, (1976).

The glycosides and polyglycosides (oligoglycosides) preparable startingfrom alkanol mixtures and olefin mixtures according to the invention arelikewise provided by the present invention.

Both the alkanol mixtures according to the invention and the polyethersprepared therefrom can be converted into anionic surfactants byesterifying (sulfating) them in a manner known per se with sulfuric acidor sulfuric acid derivatives to give acidic alkyl sulfates or alkylether sulfates, or with phosphoric acid or its derivatives to giveacidic alkyl phosphates or alkyl ether phosphates.

Sulfating reactions of alcohols have already been described, e.g. inU.S. Pat. Nos. 3,462,525, 3,420,875 or 3,524,864. Details on carryingout this reaction can be found in “Ullmann's Encyclopedia of IndustrialChemistry”, 5th edition vol. A25 (1994), pages 779-783 and in theliterature references given therein.

If sulfuric acid itself is used for the esterification, then 75 to 100%strength by weight, preferably from 85 to 98% strength by weight, ofacid is used (so-called “concentrated sulfuric acid” or “monohydrate”).The esterification can be carried out in a solvent or diluent if one isdesired for controlling the reaction, e.g. the evolution of heat. Ingeneral, the alcoholic reactant is initially introduced, and thesulfating agent is gradually added with continuous mixing. If completeesterification of the alcohol component is desired, the sulfating agentand the alkanol are used in a molar ratio from 1:1 to 1:1.5, preferablyfrom 1:1 to 1:1.2. Lesser amounts of sulfating agent can be advantageousif mixtures of alkanol alkoxylates according to the invention are usedand the intention is to prepare combinations of neutral and anionicsurfactants. The esterification is normally carried out at temperaturesfrom room temperature to 85° C., preferably in the range from 45 to 75°C.

In some instances, it may be advantageous to carry out theesterification in a low-boiling water-immiscible solvent and diluent atits boiling point, the water forming during the esterification beingdistilled off azeotropically.

Instead of sulfuric acid of the concentration given above, for thesulfation of the alkanol mixtures according to the invention, it is alsopossible, for example, to use sulfur trioxide, sulfur trioxidecomplexes, solutions of sulfur trioxide in sulfuric acid (“oleum”),chlorosulfonic acid, sulfuryl chloride or even amidosulfuric acid. Thereaction conditions are then adapted appropriately.

If sulfur trioxide is used as sulfating agent, then the reaction canalso be carried advantageously in a falling-film reactor incountercurrent, if desired also continuously.

Following esterification, the mixtures are neutralized by adding alkaliand, optionally after removal of excess alkali sulfate and any solventpresent, are worked up.

The acidic alkanol sulfates and alkanol ether sulfates and salts thereofobtained by sulfation of alkanols and alkanol ethers according to theinvention and their mixtures are likewise provided by the presentinvention.

In an analogous manner, alkanols and alkanol ethers according to theinvention and their mixtures can also be reacted (phosphated) to giveacidic phosphoric esters. Suitable phosphating agents are mainlyphosphoric acid, polyphosphoric acid and phosphorus pentoxide, but alsoPOCl₃ when the remaining acid chloride functions are subsequentlyhydrolyzed. The phosphation of alcohols has been described, for example,in Synthesis 1985, pages 449 to 488.

The acidic alkanol phosphates and alkanol ether phosphates obtained byphosphation of alkanols and alkanol ethers according to the inventionand their mixtures are also provided by the present invention.

Finally, the use of the alkanol ether mixtures, alkanol glycosides andthe acidic sulfates and phosphates of the alkanol mixtures and of thealkanol ether mixtures preparable from the olefin mixtures according tothe invention as surfactants is also provided by the present invention.

The working examples below illustrate the preparation and use of thesurfactants according to the invention.

EXAMPLE 1 Preparation of C₅/C₆-Olefins From C₄-Olefin Streams byMetathesis

A butadiene-free C₄-fraction having a total butene content of 84.2% byweight and a molar ratio of 1-butene:2-butene of 1.06 (“raffinate II”)is passed continuously, at 40° C. and 10 bar, through a tubular reactorcharged with Re₂O₇/Al₂O₃ heterogeneous catalyst. The space velocity isadjusted to 4500 kg/(m²*h). The reactor discharge is separated bydistillation and contains the following components (figures in percentby mass):

ethene: 1.15%, propene: 18.9%, butane: 15.8%, 2-butene: 19.7%, 1-butene:13.3%, i-butene: 1.00%, 2-pentene: 19.4%, methylbutene: 0.45%, 3-hexene:10.3%.

EXAMPLES 2A AND 2B Heterogeneous-catalyzed Dimerization of 3-Hexene

2A. Fixed Bed Process

An isothermally heatable reactor having a diameter of 16 mm was filledwith 100 ml of a catalyst having the following composition:

50% by weight of NiO, 34% by weight of SiO₂, 13% by weight of TiO₂, 3%by weight of Al₂O₃ (as in DE-A-43 39 713), conditioned for 24 hours at160° C. in N₂, used as 1 to 1.5 mm chips.

5 experiments were carried out, 3-hexene (99.9% strength by weight, 0.1%by weight of C₇ to C₁₁ fractions) being passed through the fixedcatalyst bed at a rate (WHSV), based on the reactor volume, of 0.25kg/l*h, and being bled out of the system at a rate of from 24 to 28 g/h.The parameters varied in the individual experiments were the reactiontemperature or the operating duration of the experiment.

Table I below shows the experimental conditions for the five experimentsand the results obtained.

TABLE I Process conditions and results in the fixed-bed process Reactionconditions Temperature [° C.] 100 120 140 160 160 C₁₂ distillatePressure [bar] 20 20 20 25 25 Operating hours 12 19 36 60 107 Liquidproduced 24 27 27 28 27 [g/h] Composition % by weight C₆ 68.5 52.7 43.657.0 73.2 0.1 C₇-C₁₁ 0.2 0.2 0.3 0.2 0.2 — C₁₂ 25.9 38.6 44.0 35.6 23.699.9 >C₁₂ 5.4 8.5 12.1 7.2 3.0 — Conversion 31.4 47.2 56.4 42.9 26.7 —C₁₂ selectivity 82.5 81.5 78.2 83.0 88.4 — [% by weight] S content inthe liquid — — — — — — produced [ppm]

The discharged product was fractionally distilled, and determination ofthe skeletal isomers of the C₁₂ fraction was carried out. Analysisrevealed 14.2% by weight of n-dodecenes, 31.8% by weight of5-methylundecenes, 29.1% by weight of 4-ethyldecenes, 6.6% by weight of5,6-dimethyldecenes, 9.3% by weight of 4-methyl-5-ethylnonenes and 3.7%by weight of diethyloctenes.

B. Suspension Process (Fluidized Bed Process)

An isothermally heatable reactor having a diameter of 20 mm and a volumeof 157 ml was filled with 30 g of a catalyst having the followingcomposition:

50% by weight of NiO, 34% by weight of SiO₂, 13% by weight of TiO₂, 3%by weight of Al₂O₃ (as in DE-A-43 39 713), conditioned for 24 hours at160° C. in N₂, used as 0.05 to 0.5 mm spray material.

6 experiments were carried out, 3-hexene (99.9% strength by weight, 0.1%by weight of C₇ to C₁₁ fractions) being passed through the catalystfluidized bed from below at a rate, based on the reactor volume, of 0.25kg/l*h. The reaction product leaving the reactor was largely recycled(recycling: feed amount varied between about 45 and 60). Parameterswhich were varied in the individual experiments were also the reactiontemperature, the feed amount, the circulation stream, the recycle rateand the WHSV of the experiment. The experiment duration was 8 hours.

Tables 2A and 2B below show the experimental conditions for the sixexperiments and the results obtained.

Tables 2

Experimental conditions and results for the suspension process.

TABLE 2A Experimental conditions Cir- Opera- Temp- Pres- cula- Recycleting Experi- erature sure Feed tion rate time ment No. [° C.] [bar][g/h] [g/h] [X:l] WHSV [h] 1 130 11.0 20 1200 60.0 0.127 8 2 130 11.0 231200 52.2 0.146 8 3 130 12.0 21 1100 52.4 0.134 8 4 130 12.2 24 110045.8 0.153 8 5 140 13.4 23 1180 51.3 0.146 8 6 150 14.1 22 1200 54.50.140 8

TABLE 2B Composition of the reaction product % % C₁₂ Experi- % % % %conver- select- ment No. C₆ % > C₆ C₁₂ C₁₈ C₂₄ sion ivity 1 83.9 0.514.3 1.1 0.2 16.1 88.82 2 80.5 0.5 16.9 1.8 0.3 19.5 86.67 3 80.3 0.417.0 1.9 0.3 19.7 86.29 4 81.6 0.5 15.5 2.0 0.3 18.4 84.24 5 75.9 0.520.4 2.6 0.5 24.1 84.65 6 71.1 0.6 24.0 3.5 0.7 28.9 83.04

The discharged product was fractionally distilled and determination ofthe skeletal isomers of the C₁₂ fraction was carried out. Analysisrevealed 14% by weight of n-dodecenes, 32% by weight of5-methylundecenes, 29% by weight of 4-ethyldecenes, 7% by weight of5,6-dimethyldecenes, 9% by weight of 4-methyl-ethylnonenes and 4% byweight of diethyloctenes.

EXAMPLE 3 Hydroformylation of the Dodecene Mixture According to theInvention

750 g of the dodecene mixture prepared as in Example 2B arehydroformylated with 3.0 g of Co₂(CO)₈ at 185° C. and 280 bar of CO/H₂(volume ratio=1:1.5) with the addition of 75 g of H₂O in a 2.5 lautoclave with lifter stirrer for 5 hours. Cobalt is removed oxidativelyfrom the reaction product using 10% strength by weight acetic acid withthe introduction of air at 90° C. The oxo product is hydrogenated withthe addition of 10% by weight of water in a 2.5 l autoclave with lifterstirrer containing 50 g of Raney nickel at 125° C. and a hydrogenpressure of 280 bar for 10 hours. The reaction product is fractionallydistilled.

450 g of a tridecanol fraction prepared in this manner arepost-hydrogenated with 3.5 g of NaBH₄.

The OH number of the resulting tridecanol is 277 mg of KOH/g. Using¹H-NMR spectroscopy, a mean degree of branching of 2.3 methylgroups/molecule was determined, corresponding to a degree of branchingof 1.3.

EXAMPLE 3A Hydroformylation of a Dodecene Mixture According to theInvention

2.12 kg of the dodecene mixture prepared as in Example 2A arehydroformylated with 8 g of Co₂(CO)₈ at 185° C. and 280 bar of CO/H₂(volume ratio 1:1) with the addition of 210 g of water in a 5 lrotary-stirrer autoclave for 5 hours. Cobalt is removed oxidatively fromthe reaction product using 10% strength by weight acetic acid with theintroduction of air at 90° C. The resulting oxo product is hydrogenatedin a 5 l tubular reactor in trickle mode over a Co/Mo fixed bed catalystat 175° C. and a hydrogen pressure of 280 bar with the addition of 10%by weight of water.

The alcohol mixture is worked up by distillation. The resultingtridecanol has an OH number of 279 mg of KOH/g; using ¹H-NMRspectroscopy, a mean degree of branching of 1.53 is measured.

EXAMPLE 3B Hydroformylation of a Dodecene Mixture According to theInvention

50 mg of rhodium biscarbonylacetylacetonate, 4.5 g of apolyethyleneimine of molar mass Mw=460,000, in which 60% of all nitrogenatoms have been acylated with lauric acid, 800 g of a dodecene mixtureprepared as in Example 2A and 196 g of toluene are heated to 150° C. ina 2.5 l autoclave with lifter stirrer under a pressure of 280 bar ofCO/H₂ (volume ratio 1:1) for 7 hours. The autoclave is then cooled,decompressed and emptied. Analysis of the resulting reaction product bygas chromatography reveals an olefin conversion of 93%. The resultingoxo product is hydrogenated in a 2.5 l tubular reactor in trickle modeover a Co/Mo fixed bed catalyst at 175° C. and a hydrogen pressure of280 bar with the addition of 10% by weight of water, and the resultingalcohol mixture is worked up by distillation. The resulting tridecanolhas a OH number of 279 mg of KOH/g; using ¹H-NMR spectroscopy, a meandegree of branching of 1.63 is measured.

EXAMPLE 3C Hydroformylation of a Dodecene Mixture According to theInvention

50 mg of rhodium biscarbonylacetylacetonate, 4.5 g of apolyethyleneimine of molar mass M_(w)=460,000, in which 60% of allnitrogen atoms have been acylated with lauric acid, 800 g of a dodecenemixture prepared as in Example 2A and 196 g of toluene are heated to160° C. in a 2.5 l autoclave with lifter stirrer under a pressure of 280bar of CO/H₂ (volume ratio 1:1) for 7 hours. The autoclave is thencooled, decompressed and emptied. Analysis of the resulting reactionproduct by gas chromatography reveals an olefin conversion of 94%. Theresulting oxo product is hydrogenated in a 2.5 l tubular reactor intrickle mode over a Co/Mo fixed bed catalyst at 175° C. and a hydrogenpressure of 280 bar with the addition of 10% by weight of water, and theresulting alcohol mixture is worked up by distillation. The resultingtridecanol has a OH number of 279 mg of KOH/g; using ¹H-NMRspectroscopy, a mean degree of branching of 1.69 is measured.

EXAMPLES 4A AND 4B Preparation of Fatty Alcohol Ethoxylates

A. Fatty Alcohol Ethoxylate Containing 7 mol of Ethylene Oxide

400 g of the alkanol mixture prepared as in Example 3 are introducedwith 1.5 g of NaOH into a dry 2 l autoclave. The autoclave contents areheated to 150° C., and 616 g of ethylene oxide are forced into theautoclave under pressure. After all of the ethylene oxide has beenintroduced into the autoclave, the autoclave is maintained at 150° C.for 30 minutes. Following cooling, the catalyst is neutralized by addingsulfuric acid.

The resulting ethoxylate is a neutral surfactant. It has a cloud pointof 72° C., measured in accordance with DIN 53917, 1% strength by weightin 10% strength by weight aqueous butyldiglycol solution. The surfacetension of a solution of 1 g/l of the substance in water is 27.3 mN/m,measured in accordance with DIN 53914.

B. Fatty Alcohol Ethoxylate Containing 3 mol of Ethylene Oxide

600 g of the alkanol mixture prepared as in Example 3B are introducedwith 1.5 g of NaOH into a dry 2 l autoclave. The autoclave contents areheated to 150° C., and 396 g of ethylene oxide are forced into theautoclave under pressure. After all of the ethylene oxide has beenintroduced into the autoclave, the autoclave is maintained at 150° C.for 30 minutes. Following cooling, the catalyst is neutralized by addingsulfuiric acid.

The resulting ethoxylate is a neutral surfactant. It has a cloud pointof 43.5° C., measured in accordance with DIN 53917, 1% strength byweight in 10% strength by weight aqueous butyldiglycol solution. Thesurface tension of a solution of 1 g/l of the substance in water is 26.1mN/m, measured in accordance with DIN 53914.

EXAMPLES 5A AND 5B Preparation of Alkyl and Alkyl Ether Phosphates.

A. Alkyl Phosphate

300 g of the alcohol mixture prepared as in Example 3B are heated to 60°C. in a stirred vessel under nitrogen, and 125 g of polyphosphoric acidare added slowly thereto. During the addition, the temperature must notexceed 65° C. Toward the end of the addition, the mixture is heated to70° C. and further stirred at this temperature for 1 hour.

The resulting product is an anionic surfactant. An aqueous solution ofthe substance in water has, at a concentration of 1 g/l, a surfacetension of 29.8 mN/m, measured in accordance with DIN 53914.

B. Alkyl Ether Phosphate

560 g of the fatty alcohol ethoxylate mixture prepared as in Example 4Bare heated to 60° C. in a stirred vessel under nitrogen, and 92 g ofpolyphosphoric acid are added slowly thereto. During the addition, thetemperature must not exceed 65° C. Toward the end of the addition, themixture is heated to 70° C. and further stirred at this temperature for1 hour.

The resulting product is an anionic surfactant. An aqueous solution ofthe substance in water has, at a concentration of 1 g/l, a surfacetension of 37.7 mN/m, measured in accordance with DIN 53914.

What is claimed is:
 1. A process for the preparation of surfactantalcohols and surfactant alcohol ethers by derivatization of olefinshaving from about 10 to 20 carbon atoms or of mixtures of such olefinsand optionally subsequent alkoxylation, which comprises a) subjecting aC₄-olefin mixture to metathesis, b) separating off olefins having from 5to 8 carbon atoms from the metathesis mixture, c) subjecting theseparated-off olefins individually or as a mixture to dimerization togive olefin mixtures having from 10 to 16 carbon atoms, d) subjectingthe resulting olefin mixture, optionally after fractionation, toderivatization to give a mixture of surfactant alcohols, and e)optionally alkoxylating the surfactant alcohols.
 2. A process as claimedin claim 1, wherein the process step a), the metathesis, is carried outin the presence of catalysts containing molybdenum, tungsten or rhenium.3. A process as claimed in claim 1, which comprises, in process step b),separating off the olefins having 5 and 6 carbon atoms.
 4. A process asclaimed in claim 1, wherein process step c), the dimerization, iscarried out with heterogeneous catalysis.
 5. A process as claimed inclaim 1, wherein a dimerization catalyst is used which contains at leastone element from subgroup VIII of the Periodic Table of the Elements,and the catalyst composition and the reaction conditions are chosen suchthat a dimer mixture is obtained which comprises less than 10% by weightof compounds which have a structural element of the formula I(vinylidene group)

in which A¹ and A² are aliphatic hydrocarbon radicals.
 6. A process asclaimed in claim 1, wherein, in process step c) olefins having 5 and 6carbon atoms are dimerized individually or in a mixture.
 7. A process asclaimed in claim 1, wherein, in process step c), 3-hexene is dimerized.8. A process as claimed in claim 1, wherein the derivatization (processstep d)) is carried out by hydroformylation.